My closed bolt Ion (really)

A little old, but not done yet either I have another version I'm making right now that should be faster to machine and devolumizes the dump chamber to high hell - something this design has had very favorable results with.

I've talked with lentyay a bit on here, I actually gave him a series of CAD cut away renderings to help him with the animation.

I'm a bit surprised nobody came in here to make a stink when the Etha was released, it's almost funny how similar they operate (apart from open vs. closed bolt)

Quote:

Originally Posted by y0da900

One problem I have run into with testing it - it traps enough residual pressure in the chamber that the bolt doesn't always retract completely, often with an eighth of an inch or so protruding into the breech. I think I have a good way around that which I will be working on hopefully tomorrow - a way that will still trap residual pressure to save it but will also allow a short period of air purge right before the bolt reaches the point where it has been hanging up.

Did you get the dimensions changed enough for this to work?

__________________
Yeah, well, that's just like, your opinion, man.

I am affiliated with Lurker Paintball. My opinions are my own and do not reflect those of LurkerPB.

Very similar operation, I have other versions of this that are all but identical to the Etha aside from this using a reducing force pressure controlled poppet and the Etha using an increasing force. The Etha is almost identical to the Phenom too.

I tweaked a little bit more on that one, but I set it aside for awhile and I'm going to treat that variation as a separate project from now on. Enough of a difference in the operation that I would rather have it evolve separately.

But a flow control valve seems to be a better control method for that one, I haven't been able to tweak the geometry enough to prevent the bolt retraction issue, but I have another variation drawn up (not built yet) that uses a multi piece firing piston that can retract in two stages that should help with things a bit as well.

AWESOME WORK! Took a stroll into CM and am just now seeing this. I have one question though

Quote:

Originally Posted by y0da900

One problem I have run into with testing it - it traps enough residual pressure in the chamber that the bolt doesn't always retract completely, often with an eighth of an inch or so protruding into the breech. I think I have a good way around that which I will be working on hopefully tomorrow - a way that will still trap residual pressure to save it but will also allow a short period of air purge right before the bolt reaches the point where it has been hanging up.

I don't get how this is possible, it looks like when the bolt is retracted (loading a ball position) the pressure behind it should be completely vented through the middle of the bolt piece. Am I missing something?

The problem happens because the bolt begins to retract as soon as the chamber pressure drops to a low enough level that the air trying to push the bolt back overpowers the chamber pressure holding it forward. This happens before the chamber is completely empty. In the version that has no powertube, the valve piston makes a seal directly with the interior of the bolt. When the bolt begins to retract, it only has to move around a quarter inch before the seal with the valve piston is remade, trapping whatever pressure was still in the chamber. It will continue trying to closed, but then acts like a bike pump trying to further compress the air trapped in the chamber, but there isn't enough force pushing the bolt closed to be able to fully compress the residual air.

Only a problem with that variation, not an issue in the ones with a powertube.

The current design doesn't have those changes - that one is a spinoff project that developed from this. This still has the powertube and no problems with captured air stopping the bolt retraction early.

Newest design does not require any threaded components, and has integrated chamber devolumizing. The firing piston has also been redesigned with one of the seals being stationary instead of 2 seals on the tail - this allows the supply air to provide a holding force when the piston is retracting to prevent the possibility of the piston bumping forward after retracting, as well as helping it to open faster. Another advantage to the new style is that there is an optional installation that lets you hide the complete assembly inside a stock Ion body with no tubing showing outside. Requires a permanent modification to the firing can to do this, as well as shortening the piece of the kit that fits into the tail of the can and putting a groove into the donut, but allows for a 100% hidden setup. All of these modifications are able to be done with a dremel tool and a 10-32 tap to deepen the threads for the rear air fitting.

Operates at ~190psi, obviously varying quite a bit depending on paint and barrel. Efficiency also varies with paint and barrel - 1,600 - 2,000 shots per tank depending on those factors at ~300FPS (I get ~1,800 with the paint I get locally in a bore matched barrel - smallest I have - shooting 295-300FPS - efficiency is exponentially related to velocity - 270 could give you ~2,200).

I'm assuming by Lucky body you mean the type that takes their own internals that are similar to an L7? If so, there is no combination of parts that will let the kits fit, I would have to make a set from scratch. Which I have done before, but won't have time to do for quite a while.

I'm assuming by Lucky body you mean the type that takes their own internals that are similar to an L7? If so, there is no combination of parts that will let the kits fit, I would have to make a set from scratch. Which I have done before, but won't have time to do for quite a while.